In a region of space

PHYSICS · Subjective · CBSE · Physics · Moving Charges and Magnetism · Moving Charges and Magnetism

Problem

In a region of space, a uniform magnetic field

B

is along the positive

x

-axis. Electrons are emitted from the origin with speed

v

at different angles. Show that the paraxial electrons are refocused on the

x

-axis at a distance

\frac{2\pi mv}{Be}

. Here,

m

is the mass of an electron and

e

is the magnitude of its charge.